Synthesis of terminal alkenes from internal alkenes and ethylene via olefin metathesis

ABSTRACT

This invention relates generally to olefin metathesis, and more particularly relates to the synthesis of terminal alkenes from internal alkenes using a cross-metathesis reaction catalyzed by a selected olefin metathesis catalyst. In one embodiment of the invention, for example, a method is provided for synthesizing a terminal olefin, the method comprising contacting an olefinic substrate comprised of at least one internal olefin with ethylene, in the presence of a metathesis catalyst, wherein the catalyst is present in an amount that is less than about 1000 ppm relative to the olefinic substrate, and wherein the metathesis catalyst has the structure of formula (II)  
                 
wherein the various substituents are as defined herein. The invention has utility, for example, in the fields of catalysis, organic synthesis, and industrial chemistry.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 60/830,944, filed Jul. 13, 2006, the disclosure of which isincorporated herein by reference.

GOVERNMENT RIGHTS

This invention was made with Government support under grant no.DE-FG36-04GO14016 awarded by the Department of Energy. The U.S.Government has certain rights in this invention.

TECHNICAL FIELD

This invention relates generally to olefin metathesis, and moreparticularly relates to the synthesis of terminal alkenes from internalalkenes using a cross-metathesis reaction catalyzed by a selected olefinmetathesis catalyst. The invention has utility in the fields ofcatalysis, organic synthesis, and industrial chemistry.

BACKGROUND

Ethenolysis is a specific cross metathesis reaction between an internalolefin and ethylene to produce terminal olefins. Scheme 1 demonstratesthe ethenolysis reaction:

Examples of ethenolysis include the conversion of a mixture of ethyleneand 2-butene into propene (as in the Phillips triolefin process and theMeta-4 process developed by the Institut Frangais du Petrole), and theconversion of a mixture of ethylene and 2,4,4-trimethyl-2-pentene intoneohexene. These processes typically use heterogeneous ill-definedolefin metathesis catalysts based on tungsten and rhenium oxides andwhich are not compatible with air, water, oxygenates, and manyfunctional groups. The ethenolysis reaction has also been implemented inthe conversion of seed oil-derived substrates such as fatty acid methylesters (FAME) into terminally unsaturated carboxylic acids (e.g.,9-decenoic acid) and terminal olefins (e.g., 1-decene). The ethenolysisof FAME was originally performed with a heterogeneous, ill-definedrhenium catalyst to give turnover numbers (TON) of about 100. Theso-called “first generation” Grubbs catalysts such asCl₂(PCy₃)₂Ru=CH—CH═CPh₂, Cl₂(PCy₃)₂Ru=CHPh (“C823”), and complexes thatcontain bicyclic phosphines, as well as first generation Grubbs-Hoveydacatalyst (“C601”), have been used in the ethenolysis of vegetableoil-derived materials. The production of 1-octene from linoleic acidusing an enzyme-mediated isomerization reaction, followed by ametathesis reaction using ethylene and various metathesis catalysts, hasalso been described. However, the conjugation present in these reactantsnecessitated a high catalyst loading and often resulted in a relativelylow yield of terminal olefin products.

It is therefore desirable to provide a convenient and effective routefor the production of terminal olefins. Compared with known metathesismethods, an ideal process would: substantially reduce the amount ofcatalyst that is needed for the cross-metathesis reaction; provide ahigh degree of selectivity for the preparation of terminal olefins frominternal olefins; and allow the use of a mixture of internal olefinsfrom a variety of sources. An ideal process would also not requireisomerization of the olefinic substrate prior to the metathesisreaction, and an ideal process would allow for the preparation ofterminal olefins directly from seed oils and from the componentmaterials of seed oils, or from non-isomerized derivatives of seed oils.

SUMMARY OF THE DISCLOSURE

Accordingly, the disclosure is directed to addressing one or more of theaforementioned issues, and, in one embodiment, provides a method forsynthesizing a terminal olefin. The method comprises contacting anolefinic substrate comprised of at least one internal olefin withethylene in the presence of a metathesis catalyst. The catalyst ispresent in an amount that is less than about 1000 ppm relative to theolefinic substrate. The metathesis catalyst has the structure of formula(II)

wherein:

m is zero, 1, or 2;

M is Ru or Os;

n1 and n2 are independently selected from zero and 1;

X¹ and X² are anionic ligands, and may be the same or different;

R¹ and R² are independently selected from H, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl;

L² and L³ are neutral electron donating ligands, and may be the same ordifferent; and

L¹ is a carbene ligand with the structure of formula (IIIa)

wherein:

Z¹ is —N(Ar¹)(R⁹) and Z² is —N(Ar²)(R^(9A)) or —C(R¹⁰)(R¹¹)(R¹²);

Ar¹ and Ar² are independently aryl substituted with at least one groupselected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂ aryl,C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl; and

R⁹, R^(9A), R¹⁰, R¹¹, and R¹² are independently selected from hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, provided that any twoof X¹, X², L¹, L², L³, R¹, R², R⁹, R^(9A), R¹⁰, R¹¹, and R¹² may betaken together to form a cycle.

In another embodiment, the invention provides a method for synthesizinga terminal olefin. The method comprises contacting, under reactionconditions effective to prepare a terminal olefin, an olefinic substratecomprising a mixture of mono-, di-, and tri-glycerides with ethylene inthe presence of a ruthenium alkylidene metathesis catalyst. The catalystcomprises an N-heterocyclic carbene ligand, and the olefinic substratecomprises at least one internal olefin.

In yet another embodiment, the invention provides a method forsynthesizing a terminal olefin. The method comprises contacting, underreaction conditions effective to prepare a terminal olefin, an olefinicsubstrate with ethylene in the presence of a ruthenium alkylidenemetathesis catalyst. The olefinic substrate comprises at least oneinternal olefin, and further comprises a seed oil or a compositionderived from a seed oil. The catalyst comprises an N-heterocycliccarbene ligand. At least about 50% of the metathesis reaction productscomprise a terminal olefin and at least about 50% of the internalolefins initially present in the reaction mixture are converted intoterminal olefins.

In a still further embodiment, the invention provides a method forsynthesizing a terminal olefin. The method comprises contacting, in thepresence of a metathesis catalyst, an olefinic substrate comprising atleast one internal olefin with ethylene. The metathesis catalyst has thestructure of formula (IIA)

wherein:

m is 0, 1, or 2;

M is Ru or Os;

n1 and n2 are independently selected from zero and 1;

X^(1A) and X^(2A) are CF₃CO₂;

R¹ and R² are independently selected from H, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl;

L² and L³ are neutral electron donating ligands; and

L^(1A) is an N-heterocyclic carbene ligand.

In a still further embodiment, the invention provides a method forsynthesizing a terminal olefin. The method comprises contacting, underreaction conditions effective to prepare a terminal olefin, an olefinicsubstrate with ethylene, in the presence of a metathesis catalyst. Theolefinic substrate comprises at least one internal olefin, and comprisesa seed oil or a composition derived from a seed oil. The metathesiscatalyst comprises an N-heterocyclic carbene ligand and is present in anamount that is less than about 50 ppm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the results from an etheneolysis reaction ofmethyl oleate and ethylene.

DETAILED DESCRIPTION OF THE INVENTION

Terminology and Definitions:

Unless otherwise indicated, the invention is not limited to specificreactants, substituents, catalysts, reaction conditions, or the like, assuch may vary. It is also to be understood that the terminology usedherein is for the purpose of describing particular embodiments only andis not intended to be limiting.

As used in the specification and the appended claims, the singular forms“a,” “an,” and “the” include plural referents unless the context clearlydictates otherwise. Thus, for example, reference to “an α-olefin”includes a single α-olefin as well as a combination or mixture of two ormore α-olefin, reference to “a substituent” encompasses a singlesubstituent as well as two or more substituents, and the like.

As used in the specification and the appended claims, the terms “forexample,” “for instance,” “such as,” or “including” are meant tointroduce examples that further clarify more general subject matter.Unless otherwise specified, these examples are provided only as an aidfor understanding the invention, and are not meant to be limiting in anyfashion.

In this specification and in the claims that follow, reference will bemade to a number of terms, which shall be defined to have the followingmeanings:

The term “alkyl” as used herein refers to a linear, branched, or cyclicsaturated hydrocarbon group typically although not necessarilycontaining 1 to about 24 carbon atoms, preferably 1 to about 12 carbonatoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,t-butyl, octyl, decyl, and the like, as well as cycloalkyl groups suchas cyclopentyl, cyclohexyl and the like. Generally, although again notnecessarily, alkyl groups herein contain 1 to about 12 carbon atoms. Theterm “lower alkyl” intends an alkyl group of 1 to 6 carbon atoms, andthe specific term “cycloalkyl” intends a cyclic alkyl group, typicallyhaving 4 to 8, preferably 5 to 7, carbon atoms. The term “substitutedalkyl” refers to alkyl substituted with one or more substituent groups,and the terms “heteroatom-containing alkyl” and “heteroalkyl” refer toalkyl in which at least one carbon atom is replaced with a heteroatom.If not otherwise indicated, the terms “alkyl” and “lower alkyl” includelinear, branched, cyclic, unsubstituted, substituted, and/orheteroatom-containing alkyl and lower alkyl, respectively. If nototherwise indicated, the terms “alkyl” and “lower alkyl” includeprimary, secondary, and tertiary alkyl and lower alkyl.

The term “alkylene” as used herein refers to a difunctional linear,branched, or cyclic alkyl group, where “alkyl” is as defined above.

The term “alkenyl” as used herein refers to a linear, branched, orcyclic hydrocarbon group of 2 to about 24 carbon atoms containing atleast one double bond, such as ethenyl, n-propenyl, isopropenyl,n-butenyl, isobutenyl, octenyl, decenyl, tetradecenyl, hexadecenyl,eicosenyl, tetracosenyl, and the like. Preferred alkenyl groups hereincontain 2 to about 12 carbon atoms. The term “lower alkenyl” intends analkenyl group of 2 to 6 carbon atoms, and the specific term“cycloalkenyl” intends a cyclic alkenyl group, preferably having 5 to 8carbon atoms. The term “substituted alkenyl” refers to alkenylsubstituted with one or more substituent groups, and the terms“heteroatom-containing alkenyl” and “heteroalkenyl” refer to alkenyl inwhich at least one carbon atom is replaced with a heteroatom. If nototherwise indicated, the terms “alkenyl” and “lower alkenyl” includelinear, branched, cyclic, unsubstituted, substituted, and/orheteroatom-containing alkenyl and lower alkenyl, respectively.

The term “alkenylene” as used herein refers to a difunctional linear,branched, or cyclic alkenyl group, where “alkenyl” is as defined above.

The term “alkynyl” as used herein refers to a linear or branchedhydrocarbon group of 2 to about 24 carbon atoms containing at least onetriple bond, such as ethynyl, n-propynyl, and the like. Preferredalkynyl groups herein contain 2 to about 12 carbon atoms. The term“lower alkynyl” intends an alkynyl group of 2 to 6 carbon atoms. Theterm “substituted alkynyl” refers to alkynyl substituted with one ormore substituent groups, and the terms “heteroatom-containing alkynyl”and “heteroalkynyl” refer to alkynyl in which at least one carbon atomis replaced with a heteroatom. If not otherwise indicated, the terms“alkynyl” and “lower alkynyl” include linear, branched, unsubstituted,substituted, and/or heteroatom-containing alkynyl and lower alkynyl,respectively.

The term “aryl” as used herein, and unless otherwise specified, refersto an aromatic substituent containing a single aromatic ring or multiplearomatic rings that are fused together, directly linked, or indirectlylinked (such that the different aromatic rings are bound to a commongroup such as a methylene or ethylene moiety). Preferred aryl groupscontain 5 to 24 carbon atoms, and particularly preferred aryl groupscontain 5 to 14 carbon atoms. Exemplary aryl groups contain one aromaticring or two fused or linked aromatic rings, e.g., phenyl, naphthyl,biphenyl, diphenylether, diphenylamine, benzophenone, and the like.“Substituted aryl” refers to an aryl moiety substituted with one or moresubstituent groups, and the terms “heteroatom-containing aryl” and“heteroaryl” refer to aryl substituents in which at least one carbonatom is replaced with a heteroatom, as will be described in furtherdetail infra.

The term “alkaryl” refers to an aryl group with an alkyl substituent,and the term “aralkyl” refers to an alkyl group with an arylsubstituent, wherein “aryl” and “alkyl” are as defined above. Preferredalkaryl and aralkyl groups contain 6 to 24 carbon atoms, particularlypreferred alkaryl and aralkyl groups contain 6 to 16 carbon atoms.Alkaryl groups include, for example, p-methylphenyl, 2,4-dimethylphenyl,p-cyclohexylphenyl, 2,7-dimethylnaphthyl, 7-cyclooctylnaphthyl,3-ethyl-cyclopenta-1,4-diene, and the like. Examples of aralkyl groupsinclude, without limitation, benzyl, 2-phenyl-ethyl, 3-phenyl-propyl,4-phenyl-butyl, 5-phenyl-pentyl, 4-phenylcyclohexyl, 4-benzylcyclohexyl,4-phenylcyclohexylmethyl, 4-benzylcyclohexylmethyl, and the like. Theterms “alkaryloxy” and “aralkyloxy” refer to substituents of the formula—OR wherein R is alkaryl or aralkyl, respectively, as just defined.

The term “acyl” refers to substituents having the formula —(CO)-alkyl,—(CO)-aryl, or —(CO)-aralkyl, and the term “acyloxy” refers tosubstituents having the formula —O(CO)-alkyl, —O(CO)-aryl, or—O(CO)-aralkyl, wherein “alkyl,” “aryl, and “aralkyl” are as definedabove.

The terms “cyclic” and “ring” refer to alicyclic or aromatic groups thatmay or may not be substituted and/or heteroatom containing, and that maybe monocyclic, bicyclic, or polycyclic. The term “alicyclic” is used inthe conventional sense to refer to an aliphatic cyclic moiety, asopposed to an aromatic cyclic moiety, and may be monocyclic, bicyclic orpolycyclic.

The terms “halo” and “halogen” are used in the conventional sense torefer to a chloro, bromo, fluoro or iodo substituent.

“Hydrocarbyl” refers to univalent hydrocarbyl radicals containing 1 toabout 30 carbon atoms, preferably 1 to about 24 carbon atoms, mostpreferably 1 to about 12 carbon atoms, including linear, branched,cyclic, saturated and unsaturated species, such as alkyl groups, alkenylgroups, aryl groups, and the like. The term “lower hydrocarbyl” intendsa hydrocarbyl group of 1 to 6 carbon atoms, preferably 1 to 4 carbonatoms, and the term “hydrocarbylene” intends a divalent hydrocarbylmoiety containing 1 to about 30 carbon atoms, preferably 1 to about 24carbon atoms, most preferably 1 to about 12 carbon atoms, includinglinear, branched, cyclic, saturated and unsaturated species. The term“lower hydrocarbylene” intends a hydrocarbylene group of 1 to 6 carbonatoms. “Substituted hydrocarbyl” refers to hydrocarbyl substituted withone or more substituent groups, and the terms “heteroatom-containinghydrocarbyl” and “heterohydrocarbyl” refer to hydrocarbyl in which atleast one carbon atom is replaced with a heteroatom. Similarly,“substituted hydrocarbylene” refers to hydrocarbylene substituted withone or more substituent groups, and the terms “heteroatom-containinghydrocarbylene” and heterohydrocarbylene” refer to hydrocarbylene inwhich at least one carbon atom is replaced with a heteroatom. Unlessotherwise indicated, the term “hydrocarbyl” and “hydrocarbylene” are tobe interpreted as including substituted and/or heteroatom-containinghydrocarbyl and hydrocarbylene moieties, respectively.

The term “heteroatom-containing” as in a “heteroatom-containinghydrocarbyl group” refers to a hydrocarbon molecule or a hydrocarbylmolecular fragment in which one or more carbon atoms is replaced with anatom other than carbon, e.g., nitrogen, oxygen, sulfur, phosphorus orsilicon, typically nitrogen, oxygen or sulfur. Similarly, the term“heteroalkyl” refers to an alkyl substituent that isheteroatom-containing, the term “heterocyclic” refers to a cyclicsubstituent that is heteroatom-containing, the terms “heteroaryl” and“heteroaromatic” respectively refer to “aryl” and “aromatic”substituents that are heteroatom-containing, and the like. It should benoted that a “heterocyclic” group or compound may or may not bearomatic, and further that “heterocycles” may be monocyclic, bicyclic,or polycyclic as described above with respect to the term “aryl.”Examples of heteroalkyl groups include alkoxyaryl,alkylsulfanyl-substituted alkyl, N-alkylated amino alkyl, and the like.Examples of heteroaryl substituents include pyrrolyl, pyrrolidinyl,pyridinyl, quinolinyl, indolyl, pyrimidinyl, imidazolyl,1,2,4-triazolyl, tetrazolyl, etc., and examples of heteroatom-containingalicyclic groups are pyrrolidino, morpholino, piperazino, piperidino,etc.

By “substituted” as in “substituted hydrocarbyl,” “substituted alkyl,”“substituted aryl,” and the like, as alluded to in some of theaforementioned definitions, is meant that in the hydrocarbyl, alkyl,aryl, or other moiety, at least one hydrogen atom bound to a carbon (orother) atom is replaced with one or more non-hydrogen substituents.Examples of such substituents include, without limitation: functionalgroups referred to herein as “Fn,” such as halo, hydroxyl, sulfhydryl,C₁-C₂₄ alkoxy, C₂-C₂₄ alkenyloxy, C₂-C₂₄ alkynyloxy, C₅-C₂₄ aryloxy,C₆-C₂₄ aralkyloxy, C₆-C₂₄ alkaryloxy, acyl (including C₂-C₂₄alkylcarbonyl (—CO-alkyl) and C₆-C₂₄ arylcarbonyl (—CO-aryl)), acyloxy(—O-acyl, including C₂-C₂₄ alkylcarbonyloxy (—O—CO-alkyl) and C₆-C₂₄arylcarbonyloxy (—O—CO-aryl)), C₂-C₂₄ alkoxycarbonyl (—(CO)—O-alkyl),C₆-C₂₄-aryloxycarbonyl (—(CO)—O-aryl), halocarbonyl (—CO)—X where X ishalo), C₂-C₂₄ alkylcarbonato (—O—(CO)—O-alkyl), C₆-C₂₄ arylcarbonato(—O—(CO)—O-aryl), carboxy (—COOH), carboxylato (—COO⁻), carbamoyl(—(CO)—NH₂), mono-(C₁-C₂₄ alkyl)-substituted carbamoyl (—(CO)—NH(C₁-C₂₄alkyl)), di-(C₁-C₂₄ alkyl)-substituted carbamoyl (—(CO)—N(C₁-C₂₄alkyl)₂), mono-(C₅-C₂₄ aryl)-substituted carbamoyl (—(CO)—NH-aryl),di-(C₅-C₂₄ aryl)-substituted carbamoyl (—(CO)—N(C₅-C₂₄ aryl)₂),di-N—(C₁-C₂₄ alkyl),N—(C₅-C₂₄ aryl)-substituted carbamoyl, thiocarbamoyl(—(CS)—NH₂), mono-(C₁-C₂₄ alkyl)-substituted thiocarbamoyl(—(CO)—NH(C₁-C₂₄ alkyl)), di-(C₁-C₂₄ alkyl)-substituted thiocarbamoyl(—(CO)—N(C₁-C₂₄ alkyl)₂), mono-(C₅-C₂₄ aryl)-substituted thiocarbamoyl(—(CO)—NH-aryl), di-(C₅-C₂₄ aryl)-substituted thiocarbamoyl(—(CO)—N(C₅-C₂₄ aryl)₂), di-N—(C₁-C₂₄ alkyl),N—(C₅-C₂₄ aryl)-substitutedthiocarbamoyl, carbamido (—NH—(CO)—NH₂), cyano(—C—N), cyanato (—O—C≡N),thiocyanato (—S—C—N), formyl (—(CO)—H), thioformyl (—(CS)—H), amino(—NH₂), mono-(C₁-C₂₄ alkyl)-substituted amino, di-(C₁-C₂₄alkyl)-substituted amino, mono-(C₅-C₂₄ aryl)-substituted amino,di-(C₅-C₂₄ aryl)-substituted amino, C₂-C₂₄ alkylamido (—NH—(CO)-alkyl),C₆-C₂₄ arylamido (—NH—(CO)-aryl), imino (—CR═NH where R=hydrogen, C₁-C₂₄alkyl, C₅-C₂₄ aryl, C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl, etc.), C₂-C₂₀alkylimino (—CR═N(alkyl), where R=hydrogen, C₁-C₂₄ alkyl, C₅-C₂₄ aryl,C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl, etc.), arylimino (—CR═N(aryl), whereR=hydrogen, C₁-C₂₀ alkyl, C₅-C₂₄ aryl, C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl,etc.), nitro (—NO₂), nitroso (—NO), sulfo (—SO₂—OH), sulfonato(—SO₂—O⁻), C₁-C₂₄ alkylsulfanyl (—S-alkyl; also termed “alkylthio”),C₅-C₂₄ arylsulfanyl (—S-aryl; also termed “arylthio”), C₁-C₂₄alkylsulfinyl (—(SO)-alkyl), C₅-C₂₄ arylsulfinyl (—(SO)-aryl), C₁-C₂₄alkylsulfonyl (—SO₂-alkyl), C₅-C₂₄ arylsulfonyl (—SO₂-aryl), boryl(—BH₂), borono (—B(OH)₂), boronato (—B(OR)₂ where R is alkyl or otherhydrocarbyl), phosphono (—P(O)(OH)₂), phosphonato (—P(O)(O⁻)₂),phosphinato (—P(O)(O⁻)), phospho (—PO₂), phosphino (—PH₂), silyl (—SiR₃wherein R is hydrogen or hydrocarbyl), and silyloxy (—O-silyl); and thehydrocarbyl moieties C₁-C₂₄ alkyl (preferably C₁-C₁₂ alkyl, morepreferably C₁-C₆ alkyl), C₂-C₂₄ alkenyl (preferably C₂-C₁₂ alkenyl, morepreferably C₂-C₆ alkenyl), C₂-C₂₄ alkynyl (preferably C₂-C₁₂ alkynyl,more preferably C₂-C₆ alkynyl), C₅-C₂₄ aryl (preferably C₅-C₁₄ aryl),C₆-C₂₄ alkaryl (preferably C₆-C₁₆ alkaryl), and C₆-C₂₄ aralkyl(preferably C₆-C₁₆ aralkyl).

In addition, the aforementioned functional groups may, if a particulargroup permits, be further substituted with one or more additionalfunctional groups or with one or more hydrocarbyl moieties such as thosespecifically enumerated above. Analogously, the above-mentionedhydrocarbyl moieties may be further substituted with one or morefunctional groups or additional hydrocarbyl moieties such as thosespecifically enumerated.

“Optional” or “optionally” means that the subsequently describedcircumstance may or may not occur, so that the description includesinstances where the circumstance occurs and instances where it does not.For example, the phrase “optionally substituted” means that anon-hydrogen substituent may or may not be present on a given atom, and,thus, the description includes structures wherein a non-hydrogensubstituent is present and structures wherein a non-hydrogen substituentis not present.

Methods and Compositions:

Accordingly, the invention provides an olefin cross-metathesis methodfor synthesizing a terminal olefin from ethylene and an olefinicsubstrate comprised of at least one internal olefin. The reactions arecarried out catalytically, in the presence of a ruthenium alkylidenemetathesis catalyst.

In a first embodiment of the invention, then, the olefin metathesisreaction is carried out by contacting the at least one internal olefinwith ethylene in the presence of the metathesis catalyst under reactionconditions effective to allow cross-metathesis to occur.

The olefin metathesis catalyst for carrying out the cross-metathesisreactions of the invention is preferably a Group 8 transition metalcomplex having the structure of formula (II)

wherein:

m is zero, 1, or 2;

M is Ru or Os;

n1 and n2 are independently selected from zero and 1;

X¹ and X² are anionic ligands and may be the same or different;

R¹ and R² are independently selected from H, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl;

L² and L³ are neutral electron donating ligands and may be the same ordifferent; and

L¹ is a carbene ligand with the structure of formula (IIIa)

wherein:

Z¹ is —N(Ar¹)(R⁹) and Z² is —N(Ar²)(R^(9A)) or —C(R¹⁰)(R¹¹)(R¹²);

Ar¹ and Ar² are independently aryl substituted with at least one groupselected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂ aryl,C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl; and

R⁹, R^(9A), R¹⁰, R¹¹, and R¹² are independently selected from hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl,

wherein any two of X, X², L¹, L², L³, R¹, R², R⁹, R^(9A), R¹⁰, R¹¹, andR¹² may be taken together to form a cycle.

Preferred catalysts contain Ru or Os as the Group 8 transition metal,with Ru particularly preferred.

Numerous embodiments of the catalysts useful in the reactions of theinvention are described in more detail infra. For the sake ofconvenience, the catalysts are described in groups, but it should beemphasized that these groups are not meant to be limiting in any way.That is, any of the catalysts useful in the invention may fit thedescription of more than one of the groups described herein.

A first group of catalysts having the structure of formula (II) iscommonly referred to as Second Generation Grubbs-type catalysts. Forcatalysts of the first group, M, n1, n2, and m are as described above,and X¹, X², L¹, L², L³, R¹, and R² are further described as follows.

L² is selected from phosphine, sulfonated phosphine, phosphite,phosphinite, phosphonite, arsine, stibine, ether, amine, amide, imine,sulfoxide, carboxyl, nitrosyl, pyridine, substituted pyridine,imidazole, substituted imidazole, pyrazine, and thioether. Exemplaryligands are trisubstituted phosphines.

X¹ and X² are anionic ligands, and may be the same or different, or arelinked together to form a cyclic group, typically although notnecessarily a five- to eight-membered ring. In preferred embodiments, X¹and X² are each independently hydrogen, halide, or one of the followinggroups: C₁-C₂₀ alkyl, C₅-C₂₄ aryl, C₁-C₂₀ alkoxy, C₅-C₂₄ aryloxy, C₂-C₂₀alkoxycarbonyl, C₆-C₂₄ aryloxycarbonyl, C₂-C₂₄ acyl, C₂-C₂₄ acyloxy,C₁-C₂₀ alkylsulfonato, C₅-C₂₄ arylsulfonato, C₁-C₂₀ alkylsulfanyl,C₅-C₂₄ arylsulfanyl, C₁-C₂₀ alkylsulfinyl, or C₅-C₂₄ arylsulfinyl.Optionally, X¹ and X² may be substituted with one or more moietiesselected from C₁-C₁₂ alkyl, C₁-C₁₂ alkoxy, C₅-C₂₄ aryl, and halide,which may, in turn, with the exception of halide, be further substitutedwith one or more groups selected from halide, C₁-C₆ alkyl, C₁-C₆ alkoxy,and phenyl. In more preferred embodiments, X¹ and X² are halide,benzoate, C₂-C₆ acyl, C₂-C₆ alkoxycarbonyl, C₁-C₆ alkyl, phenoxy, C₁-C₆alkoxy, C₁-C₆ alkylsulfanyl, aryl, or C₁-C₆ alkylsulfonyl. In even morepreferred embodiments, X¹ and X² are each halide, CF₃CO₂, CH₃CO₂,CFH₂CO₂, (CH₃)₃CO, (CF₃)₂(CH₃)CO, (CF₃)(CH₃)₂CO, PhO, MeO, EtO,tosylate, mesylate, or trifluoromethane-sulfonate.

R¹ and R² are independently selected from hydrogen, hydrocarbyl (e.g.,C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₅-C₂₄ aryl, C₆-C₂₄alkaryl, C₆-C₂₄ aralkyl, etc.), substituted hydrocarbyl (e.g.,substituted C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₅-C₂₄ aryl,C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl, etc.), heteroatom-containing hydrocarbyl(e.g., heteroatom-containing C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀alkynyl, C₅-C₂₄ aryl, C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl, etc.), andsubstituted heteroatom-containing hydrocarbyl (e.g., substitutedheteroatom-containing C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl,C₅-C₂₄ aryl, C₆-C₂₄ alkaryl, C₆-C₂₄ aralkyl, etc.), and functionalgroups. R¹ and R² may also be linked to form a cyclic group, which maybe aliphatic or aromatic, and may contain substituents and/orheteroatoms. Generally, such a cyclic group will contain 4 to 12,preferably 5, 6, 7, or 8 ring atoms.

In preferred catalysts, R¹ is hydrogen and R² is selected from C₁-C₂₀alkyl, C₂-C₂₀ alkenyl, and C₅-C₂₄ aryl, more preferably C₁-C₆ alkyl,C₂-C₆ alkenyl, and C₅-C₁₄ aryl. Still more preferably, R² is phenyl,vinyl, methyl, isopropyl, or t-butyl, optionally substituted with one ormore moieties selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, phenyl, and afunctional group Fn as defined earlier herein. Most preferably, R² isphenyl or vinyl substituted with one or more moieties selected frommethyl, ethyl, chloro, bromo, iodo, fluoro, nitro, dimethylamino,methyl, methoxy, and phenyl. Optimally, R² is phenyl or —C═C(CH₃)₂.

Any two or more (typically two, three, or four) of X¹, X², L¹, L², L³,R¹, and R² can be taken together to form a cyclic group. When any of X¹,X², L¹, L², L³, R¹, and R² are linked to form cyclic groups, thosecyclic groups may contain 4 to 12, preferably 4, 5, 6, 7 or 8 atoms, ormay comprise two or three of such rings, which may be either fused orlinked. The cyclic groups may be aliphatic or aromatic, and may beheteroatom-containing and/or substituted. The cyclic group may, in somecases, form a bidentate ligand or a tridentate ligand. Examples ofbidentate ligands include, but are not limited to, bisphosphines,dialkoxides, alkyldiketonates, and aryldiketonates.

L¹ is a carbene ligand with the structure of formula (IIIa)

wherein Z¹ is —N(Ar¹)(R⁹) and Z² is —N(Ar²)(R^(9A)) or—C(R¹⁰)(R¹¹)(R¹²), Ar¹ and Ar² are aryl substituted with at least onegroup selected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl, and Ar¹ and Ar² may be thesame or different. R⁹, R^(9A), R¹⁰, R¹¹, and R¹² are independentlyselected from hydrogen, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl. Furthermore, any two of X¹, X², L¹, L², L³, R¹, R², R⁹,R^(9A), R¹⁰, R¹¹, and R¹² may be taken together to form a cycle.

For example, Z¹ is —N(Ar¹)(R⁹), Z² is —C(R¹⁰)(R¹¹)(R¹²), and R⁹ and R¹²are linked. The linkage formed by R⁹ and R¹² has the structure

such that L¹ has the structure of formula (IIIb)

wherein α is an optional double bond, and R¹³, R¹⁴, R¹⁵, and R¹⁶ areindependently selected from hydrogen, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl, provided that R¹⁴ and R¹⁶ are notpresent if a is present, and provided that any two or more of Ar¹, R¹⁰,R¹¹, R¹³, R¹⁴, R¹⁵, and R¹⁶ may be taken together to form a cyclicgroup. For example, R¹⁰ and R¹¹ are taken together to form a cyclicgroup, such as a six-membered cyclic group.

In a preferred embodiment, Ar¹ has the structure of formula (VIIa)

wherein

represents the attachment point to N in formula (IIIb), R¹⁷ and R¹⁸ areindependently selected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl, and R¹⁹, R²⁰,and R²¹ are independently selected from H, C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl,C₂-C₁₂ alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl. Forexample, R¹⁹, R²⁰, and R²¹ are H such that Ar¹ has the structure offormula (VIIb)

wherein the wavy line represents the attachment point to N in formula(IIIb) and R¹⁷ and R¹⁸ are independently selected from C₂-C₁₂ alkyl,C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂alkaryl. In a more preferred embodiment, R¹⁷ and R¹⁸ are independentlyC₂-C₁₂ alkyl; for example, R¹⁷ and R¹⁸ are both ethyl.

As another example, Z¹ is —N(Ar¹)(R⁹) and Z² is —N(Ar²)(R^(9A)). In apreferred embodiment, R⁹ and R^(9A) are linked such that L¹ has thestructure of formula (IIIc)

wherein α is an optional double bond, Ar² is aryl substituted with atleast one group selected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl, and R¹³, R¹⁴,R¹⁵, and R¹⁶ are as described previously. In a preferred embodiment, L¹has the formula of (IIId)

wherein R²², R²³, R²⁷ and R²⁸ are independently selected from C₂-C₁₂alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, andC₆-C₁₂ alkaryl, and R²⁴, R²⁵, R²⁶, R²⁹, R³⁰, and R³¹ are independentlyselected from H, C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl. For example, α is not present,and L¹ has the structure of formula (IIId-1)

As a further example, α is not present, and R¹³, R¹⁴, R¹⁵, R¹⁶, R²⁴,R²⁵, R²⁶, R²⁹, R³⁰, and R³¹ are each H such that L¹ has the structure offormula (IIIe)

wherein R²², R²³, R²⁷, and R²⁸ are independently selected from C₂-C₁₂alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, andC₆-C₁₂ alkaryl. As a further example, R²², R²³, R²⁷, and R²⁸ are eachindependently C₃-C₁₂ secondary alky or C₄-C₁₂ tertiary alkyl, and as astill further example, R²², R²³, R²⁷, and R²⁸ are isopropyl.

Examples of N-heterocyclic carbene ligands suitable as L¹ also includethe following:

In a second group of catalysts having the structure of formula (II), M,m, n, X¹, X², L¹, R¹, and R² are as defined for the first group ofcatalysts having the structure of formula (II), and L² and L³ are weaklycoordinating neutral electron donor ligands in the form of optionallysubstituted heterocyclic groups. Again, n is zero or 1, such that L³ mayor may not be present. Generally, in the second group of catalysts, L²and L³ are optionally substituted five- or six-membered monocyclicgroups containing 1 to 4, preferably 1 to 3, most preferably 1 to 2heteroatoms, or are optionally substituted bicyclic or polycyclicstructures composed of 2 to 5 such five- or six-membered monocyclicgroups. If the heterocyclic group is substituted, it should not besubstituted on a coordinating heteroatom, and any one cyclic moietywithin a heterocyclic group will generally not be substituted with morethan 3 substituents.

Examples of L² and L³ include, without limitation, heterocyclescontaining nitrogen, sulfur, oxygen, or a mixture thereof.

Examples of nitrogen-containing heterocycles appropriate for L² and L³include pyridine, bipyridine, pyridazine, pyrimidine, bipyridamine,pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, pyrrole,2H-pyrrole, 3H-pyrrole, pyrazole, 2H-imidazole, 1,2,3-triazole,1,2,4-triazole, indole, 3H-indole, 1H-isoindole, cyclopenta(b)pyridine,indazole, quinoline, bisquinoline, isoquinoline, bisisoquinoline,cinnoline, quinazoline, naphthyridine, piperidine, piperazine,pyrrolidine, pyrazolidine, quinuclidine, imidazolidine, picolylimine,purine, benzimidazole, bisimidazole, phenazine, acridine, and carbazole.

Examples of sulfur-containing heterocycles appropriate for L² and L³include thiophene, 1,2-dithiole, 1,3-dithiole, thiepin,benzo(b)thiophene, benzo(c)thiophene, thionaphthene, dibenzothiophene,2H-thiopyran, 4H-thiopyran, and thioanthrene.

Examples of oxygen-containing heterocycles appropriate for L² and L³include 2H-pyran, 4H-pyran, 2-pyrone, 4-pyrone, 1,2-dioxin, 1,3-dioxin,oxepin, furan, 2H-1-benzopyran, coumarin, coumarone, chromene,chroman-4-one, isochromen-1-one, isochromen-3-one, xanthene,tetrahydrofuran, 1,4-dioxan, and dibenzofuran.

Examples of mixed heterocycles appropriate for L² and L³ includeisoxazole, oxazole, thiazole, isothiazole, 1,2,3-oxadiazole,1,2,4-oxadiazole, 1,3,4-oxadiazole, 1,2,3,4-oxatriazole,1,2,3,5-oxatriazole, 3H-1,2,3-dioxazole, 3H-1,2-oxathiole,1,3-oxathiole, 4H-1,2-oxazine, 2H-1,3-oxazine, 1,4-oxazine,1,2,5-oxathiazine, o-isooxazine, phenoxazine, phenothiazine,pyrano[3,4-b]pyrrole, indoxazine, benzoxazole, anthranil, andmorpholine.

Preferred L² and L³ ligands are aromatic nitrogen-containing andoxygen-containing heterocycles, and particularly preferred L² and L³ligands are monocyclic N-heteroaryl ligands that are optionallysubstituted with 1 to 3, preferably 1 or 2, substituents. Specificexamples of particularly preferred L² and L³ ligands are pyridine andsubstituted pyridines, such as 3-bromopyridine, 4-bromopyridine,3,5-dibromopyridine, 2,4,6-tribromopyridine, 2,6-dibromopyridine,3-chloropyridine, 4-chloropyridine, 3,5-dichloropyridine,2,4,6-trichloropyridine, 2,6-dichloropyridine, 4-iodopyridine,3,5-diiodopyridine, 3,5-dibromo-4-methylpyridine,3,5-dichloro-4-methylpyridine, 3,5-dimethyl-4-bromopyridine,3,5-dimethylpyridine, 4-methylpyridine, 3,5-diisopropylpyridine,2,4,6-trimethylpyridine, 2,4,6-triisopropylpyridine,4-(tert-butyl)pyridine, 4-phenylpyridine, 3,5-diphenylpyridine,3,5-dichloro-4-phenylpyridine, and the like.

In general, any substituents present on L² and/or L³ are selected fromhalo, C₁-C₂₀ alkyl, substituted C₁-C₂₀ alkyl, C₁-C₂₀ heteroalkyl,substituted C₁-C₂₀ heteroalkyl, C₅-C₂₄ aryl, substituted C₅-C₂₄ aryl,C₅-C₂₄ heteroaryl, substituted C₅-C₂₄ heteroaryl, C₆-C₂₄ alkaryl,substituted C₆-C₂₄ alkaryl, C₆-C₂₄ heteroalkaryl, substituted C₆-C₂₄heteroalkaryl, C₆-C₂₄ aralkyl, substituted C₆-C₂₄ aralkyl, C₆-C₂₄heteroaralkyl, substituted C₆-C₂₄ heteroaralkyl, and functional groups,with suitable functional groups including, without limitation, C₁-C₂₀alkoxy, C₅-C₂₄ aryloxy, C₂-C₂₀ alkylcarbonyl, C₆-C₂₄ arylcarbonyl,C₂-C₂₀ alkylcarbonyloxy, C₆-C₂₄ arylcarbonyloxy, C₂-C₂₀ alkoxycarbonyl,C₆-C₂₄ aryloxycarbonyl, halocarbonyl, C₂-C₂₀ alkylcarbonato, C₆-C₂₄arylcarbonato, carboxy, carboxylato, carbamoyl, mono-(C₁-C₂₀alkyl)-substituted carbamoyl, di-(C₁-C₂₀ alkyl)-substituted carbamoyl,di-N—(C₁-C₂₀ alkyl), N—(C₅-C₂₄ aryl)-substituted carbamoyl, mono-(C₅-C₂₄aryl)-substituted carbamoyl, di-(C₆-C₂₄ aryl)-substituted carbamoyl,thiocarbamoyl, mono-(C₁-C₂₀ alkyl)-substituted thiocarbamoyl, di-(C₁-C₂₀alkyl)-substituted thiocarbamoyl, di-N—(C₁-C₂₀ alkyl)-N—(C₆-C₂₄aryl)-substituted thiocarbamoyl, mono-(C₆-C₂₄ aryl)-substitutedthiocarbamoyl, di-(C₆-C₂₄ aryl)-substituted thiocarbamoyl, carbamido,formyl, thioformyl, amino, mono-(C₁-C₂₀ alkyl)-substituted amino,di-(C₁-C₂₀ alkyl)-substituted amino, mono-(C₅-C₂₄ aryl)-substitutedamino, di-(C₅-C₂₄ aryl)-substituted amino, di-N—(C₁-C₂₀ alkyl),N—(C₅-C₂₄aryl)-substituted amino, C₂-C₂₀ alkylamido, C₆-C₂₄ arylamido, imino,C₁-C₂₀ alkylimino, C₅-C₂₄ arylimino, nitro, and nitroso. In addition,two adjacent substituents may be taken together to form a ring,generally a five- or six-membered alicyclic or aryl ring, optionallycontaining 1 to 3 heteroatoms and 1 to 3 substituents as above.

Preferred substituents on L² and L³ include, without limitation, halo,C₁-C₁₂ alkyl, substituted C₁-C₁₂ alkyl, C₁-C₁₂ heteroalkyl, substitutedC₁-C₁₂ heteroalkyl, C₅-C₁₄ aryl, substituted C₅-C₁₄ aryl, C₅-C₁₄heteroaryl, substituted C₅-C₁₄ heteroaryl, C₆-C₁₆ alkaryl, substitutedC₆-C₁₆ alkaryl, C₆-C₁₆ heteroalkaryl, substituted C₆-C₁₆ heteroalkaryl,C₆-C₁₆ aralkyl, substituted C₆-C₁₆ aralkyl, C₆-C₁₆ heteroaralkyl,substituted C₆-C₁₆ heteroaralkyl, C₁-C₁₂ alkoxy, C₅-C₁₄ aryloxy, C₂-C₁₂alkylcarbonyl, C₆-C₁₄ arylcarbonyl, C₂-C₁₂ alkylcarbonyloxy, C₆-C₁₄arylcarbonyloxy, C₂-C₁₂ alkoxycarbonyl, C₆-C₁₄ aryloxycarbonyl,halocarbonyl, formyl, amino, mono-(C₁-C₁₂ alkyl)-substituted amino,di-(C₁-C₁₂ alkyl)-substituted amino, mono-(C₅-C₁₄ aryl)-substitutedamino, di-(C₅-C₁₄ aryl)-substituted amino, and nitro.

Of the foregoing, the most preferred substituents are halo, C₁-C₆ alkyl,C₁-C₆ haloalkyl, C₁-C₆ alkoxy, phenyl, substituted phenyl, formyl,N,N-diC₁-C₆ alkyl)amino, nitro, and nitrogen heterocycles as describedabove (including, for example, pyrrolidine, piperidine, piperazine,pyrazine, pyrimidine, pyridine, pyridazine, etc.).

L² and L³ may also be taken together to form a bidentate or multidentateligand containing two or more, generally two, coordinating heteroatomssuch as N, O, S, or P, with preferred such ligands being diimine ligandsof the Brookhart type. One representative bidentate ligand has thestructure of formula (VIII)

wherein R³², R³³, R³⁴, and R³⁵ are independently hydrocarbyl (e.g.,C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₅-C₂₄ aryl, C₆-C₂₄alkaryl, or C₆-C₂₄ aralkyl), substituted hydrocarbyl (e.g., substitutedC₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₅-C₂₄ aryl, C₆-C₂₄alkaryl, or C₆-C₂₄ aralkyl), heteroatom-containing hydrocarbyl (e.g.,C₁-C₂₀ heteroalkyl, C₅-C₂₄ heteroaryl, heteroatom-containing C₆-C₂₄aralkyl, or heteroatom-containing C₆-C₂₄ alkaryl), or substitutedheteroatom-containing hydrocarbyl (e.g., substituted C₁-C₂₀ heteroalkyl,C₅-C₂₄ heteroaryl, heteroatom-containing C₆-C₂₄ aralkyl, orheteroatom-containing C₆-C₂₄ alkaryl), or (1) R³² and R³³, (2) R³⁴ andR³⁵, (3) R³³ and R³⁴, or (4) both R³² and R³³, and R³⁴ and R³⁵, may betaken together to form a ring, i.e., an N-heterocycle. Preferred cyclicgroups in such a case are five- and six-membered rings, typicallyaromatic rings.

A third group of catalysts having the structure of formula (II),includes catalysts wherein M, n1, n2, m, X¹, X², R¹, R², L¹, L², and L³are as defined for any of the previously defined catalysts, and two ofthe substituents are taken together to form a bidentate ligand or atridentate ligand.

Examples of bidentate ligands include, but are not limited to,bisphosphines, dialkoxides, alkyldiketonates, and aryldiketonates.Specific examples include —P(Ph)₂CH₂CH₂P(Ph)₂—, —As(Ph)₂CH₂CH₂As(Ph₂)—,—P(Ph)₂CH₂CH₂C(CF₃)₂O—, binaphtholate dianions, pinacolate dianions,—P(CH₃)₂(CH₂)₂P(CH₃)₂—, and —OC(CH₃)₂(CH₃)₂CO—. Preferred bidentateligands are —P(Ph)₂ CH₂CH₂P(Ph)₂— and —P(CH₃)₂(CH₂)₂P(CH₃)₂—. Tridentateligands include, but are not limited to, (CH₃)₂NCH₂CH₂P(Ph)CH₂CH₂N(CH₃)₂. Other preferred tridentate ligands are thosein which any three of X¹, X², L¹, L², L³, R¹, and R² (e.g., X¹, L¹, andL²) are taken together to be cyclopentadienyl, indenyl, or fluorenyl,each optionally substituted with C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₁-C₂₀alkyl, C₅-C₂₀ aryl, C₁-C₂₀ alkoxy, C₂-C₂₀ alkenyloxy, C₂-C₂₀ alkynyloxy,C₅-C₂₀ aryloxy, C₂-C₂₀ alkoxycarbonyl, C₁-C₂₀ alkylthio, C₁-C₂₀alkylsulfonyl, or C₁-C₂₀ alkylsulfinyl, each of which may be furthersubstituted with C₁-C₆ alkyl, halide, C₁-C₆ alkoxy or with a phenylgroup optionally substituted with halide, C₁-C₆ alkyl, or C₁-C₆ alkoxy.More preferably, in compounds of this type, X, L¹, and L² are takentogether to be cyclopentadienyl or indenyl, each optionally substitutedwith vinyl, C₁-C₁₀ alkyl, C₅-C₂₀ aryl, C₁-C₁₀ carboxylate, C₂-C₁₀alkoxycarbonyl, C₁-C₁₀ alkoxy, or C₅-C₂₀ aryloxy, each optionallysubstituted with C₁-C₆ alkyl, halide, C₁-C₆ alkoxy or with a phenylgroup optionally substituted with halide, C₁-C₆ alkyl or C₁-C₆ alkoxy.Most preferably, X, L¹ and L² may be taken together to becyclopentadienyl, optionally substituted with vinyl, hydrogen, methyl,or phenyl. Tetradentate ligands include, but are not limited toO₂C(CH₂)₂P(Ph)(CH₂)₂P(Ph)(CH₂)₂CO₂, phthalocyanines, and porphyrins.

For example, m is zero, and L² and R² are taken together to form acycle. Catalysts of this type are commonly called “Grubbs-Hoveyda”catalysts, and have the structure of formula (IIa)

wherein Q is selected from hydrocarbylene, substituted hydrocarbylene,heteroatom-containing hydrocarbylene, and substitutedheteroatom-containing hydrocarbylene, wherein two or more substituentson adjacent atoms within Q may also be taken together to form anadditional, optionally substituted cyclic structure. For example,Grubbs-Hoveyda catalysts may have the structure of formula (IIb)

Further examples of Grubbs-Hoveyda-type catalysts include the following:

wherein L¹, X¹, X², and M are as described for any of the other groupsof catalysts.

In addition to the catalysts that have the structure of formula (II), asdescribed above, other transition metal carbene complexes may be used inthe reactions disclosed herein, including:

neutral ruthenium or osmium metal carbene complexes containing metalcenters that are formally in the +2 oxidation state, have an electroncount of 16, are penta-coordinated, and are of the general formula (IX);

neutral ruthenium or osmium metal carbene complexes containing metalcenters that are formally in the +2 oxidation state, have an electroncount of 18, are hexa-coordinated, and are of the general formula (X)

cationic ruthenium or osmium metal carbene complexes containing metalcenters that are formally in the +2 oxidation state, have an electroncount of 14, are tetra-coordinated, and are of the general formula (XI);and

cationic ruthenium or osmium metal carbene complexes containing metalcenters that are formally in the +2 oxidation state, have an electroncount of 14, are penta-coordinated, and are of the general formula (XII)

wherein: X¹, X², L¹, L², n, L³, R¹, and R² are as defined for any of thepreviously defined four groups of catalysts; r and s are independentlyzero or 1; t is an integer in the range of zero to 5; Y is anynon-coordinating anion (e.g., a halide ion, BF₄ ⁻, etc.); Z¹ and Z² areindependently selected from —O—, —S—, —NR²—, —PR²—, —P(═O)R²—, —P(OR²)—,—P(═O)(OR²)—, —C(═O)—, —C(═O)O—, —OC(═O)—, —OC(═O)O—, —S(═O)—, and—S(═O)₂—; Z³ is any cationic moiety such as —P(R²)₃, or —N(R²)₃; and anytwo or more of X¹, X², L¹, L², L³, n, Z¹, Z², Z³, R¹, and R² may betaken together to form a cyclic group, e.g., a multidentate ligand, andwherein any one or more of X¹, X², L¹, L², n, L³, Z¹, Z², Z³, R¹, and R²may be attached to a support.

As is understood in the field of catalysis, suitable solid supports forany of the catalysts described herein may be of synthetic,semi-synthetic, or naturally occurring materials, which may be organicor inorganic, e.g., polymeric, ceramic, or metallic. Attachment to thesupport will generally, although not necessarily, be covalent, and thecovalent linkage may be direct or indirect, if indirect, typicallythrough a functional group on a support surface.

Non-limiting examples of catalysts that may be used in the reactions ofthe invention include the following, which for convenience areidentified throughout this disclosure by reference to their molecularweight:

In the foregoing molecular structures and formulae, Ph representsphenyl, Cy represents cyclohexyl, i-Pr represents isopropyl, Etrepresents ethyl, t-Bu represents tertiary butyl, and py representspyridine (coordinated through the N atom).

Further examples of catalysts useful in the reactions of the inventioninclude the following: ruthenium (II)[1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene) (triphenylphosphine) (C830); ruthenium (II) dichloro(tricyclohexylphosphine) (o-isopropoxyphenylmethylene) (C601), andruthenium (II) (1, 3-bis-(2,4,6,-trimethylphenyl)-2-imidazolidinylidene)dichloro (phenylmethylene) (bis 3-bromopyridine (C884)).

The transition metal complexes used as catalysts herein can be preparedby several different methods, such as those described by Schwab et al.(1996) J. Am. Chem. Soc. 118:100-110, Scholl et al. (1999) Org. Lett.6:953-956, Sanford et al. (2001) J. Am. Chem. Soc. 123:749-750, U.S.Pat. No. 5,312,940 and U.S. Pat. No. 5,342,909. Also see U.S. PatentPublication No. 2003/0055262 to Grubbs et al. filed Apr. 16, 2002 for“Group 8 Transition Metal Carbene Complexes as Enantioselective OlefinMetathesis Catalysts”, International Patent Publication No. WO 02/079208application Ser. No. 10/115,581 to Grubbs, Morgan, Benitez, and Louie,filed Apr. 2, 2002, for “One-Pot Synthesis of Group 8 Transition MetalCarbene Complexes Useful as Olefin Metathesis Catalysts,” commonlyassigned herewith to the California Institute of Technology. Preferredsynthetic methods are described in International Patent Publication No.WO 03/11455A1 to Grubbs et al. for “Hexacoordinated Ruthenium or OsmiumMetal Carbene Metathesis Catalysts,” published Feb. 13, 2003.

Reactants:

The olefinic substrate comprises at least one internal olefin, and mayhave 2 or more internal olefins. For example, the olefinic substrate maycomprise in the range of 2 to about 15, 2 to about 10, or 2 to about 5internal olefins. By “internal olefin” is meant an olefin wherein eachof the olefinic carbons is substituted by at least one non-hydrogensubstituent. The non-hydrogen substituents are selected fromhydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,substituted heteroatom-containing hydrocarbyl, and functional groups.The internal olefin is therefore at least disubstituted, and may furtherinclude additional non-hydrogen substituents such that the internalolefin is tri- or tetra-substituted. Each of the substituents on theinternal olefinic carbons may be further substituted as described supra.The internal olefin may be in the Z- or E-configuration. When theolefinic substrate comprises a plurality of internal olefins, theolefinic substrate may comprise a mixture of internal olefins (varyingin stereochemistry and/or substituent identity), or may comprise aplurality of identical internal olefins.

The olefinic substrate may be a single compound or a mixture ofcompounds. The olefinic substrate may be hydrophobic or hydrophilic,although in a preferred embodiment, the olefinic substrate ishydrophobic.

For example, the olefinic substrate may be represented by the formula(R^(I))(R^(II))C═C(R^(III))(R^(IV)), wherein R^(I), R^(II), R^(III), andR^(IV) are independently selected from H, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, substitutedheteroatom-containing hydrocarbyl, and functional groups, provided thatat least one of R^(I) or R^(II) and at least one of R^(III) or R^(IV) isother than H. In a preferred embodiment, either R^(I) or R^(II) andeither R^(III) or R^(IV) is H, such that the internal olefin isdi-substituted.

As another example, the olefinic substrate is an ester of glycerol (a“glyceride”), and has the structure of formula (I)

wherein R^(V), R^(VI), and R^(VII) are independently selected fromhydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containinghydrocarbyl, substituted heteroatom-containing hydrocarbyl, andfunctional groups, provided that at least one of R^(V), R^(VI), andR^(VII) is other than hydrogen and comprises an internal olefin. In apreferred embodiment, the olefinic substrate comprises glycerolesterified with 1, 2, or 3 fatty acids, such that the olefinic substrateis a monoacylglycerol, diacylglycerol, or triacylglycerol (i.e., amonoglyceride, diglyceride, or triglyceride, respectively), or a mixturethereof. Each fatty acid-derived fragment of the olefinic substrate mayindependently be saturated, monounsaturated, or polyunsaturated, and mayfurthermore derive (or be derivable) from naturally-occurring fattyacids or from synthetic fatty acids. For example, the olefinic substratemay comprise glycerol esterified with one, two, or three fatty acidsthat are independently selected from CH₃(CH₂)_(n)COOH, where n is 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22,palmitoleic acid, vaccenic acid, erucic acid, oleic acid,alpha-linolenic acid, gamma-linolenic acid, linoleic acid, gadoleicacid, arachidonic acid, docosahexaenoic acid (i.e., DHA),eicosapentaenoic acid (i.e., EPA), and CH₃—R^(VIII)—COOH, where R^(VIII)is substituted or unsubstituted C₂-C₂₄ alkenylene. The olefinicsubstrate may be solid (e.g., a fat) or liquid (e.g., an oil).

Preferred olefinic substrates are seed oils, or are compounds thatderive from seed oils.

The olefinic substrate may be a compound or mixture of compounds that isderived from a seed oil or glyceride using any one or combination ofmethods well known in the chemical arts. Such methods includesaponification, esterification, hydrogenation, isomerization, oxidation,and reduction. For example, the olefinic substrate may the carboxylicacid or mixture of carboxylic acids that result from the saponificationof a monoacylglycerol, diacylglycerol, triacylglycerol, or mixturethereof. In a preferred embodiment, the olefinic substrate is a fattyacid methyl ester (FAME), i.e., the methyl ester of a carboxylic acidthat is derived from a glyceride. Sunflower FAME, safflower FAME, soyFAME (i.e., methyl soyate), and canola FAME are examples of sucholefinic substrates. In addition, preferred olefinic substrates includeseed oil-derived compounds such as methyl oleate.

Sources of unsaturated esters of glycerol include synthesized oils,natural oils (e.g., seed oils, vegetable oils), animal fats, similarsources and any combinations thereof. Representative examples ofvegetable oils include canola oil, rapeseed oil, coconut oil, corn oil,cottonseed oil, olive oil, palm oil, peanut oil, safflower oil, sesameoil, soybean oil, sunflower oil, linseed oil, palm kernel oil, tung oil,castor oil, combinations of these, and the like. Representative examplesof animal fats include lard, tallow, chicken fat, yellow grease, fishoil, combinations of these, and the like. A representative example of asynthesized oil includes tall oil, which is a byproduct of wood pulpmanufacture.

The at least one internal olefin is reacted with ethylene, across-metathesis partner, in the cross-metathesis reactions of theinvention. Ethylene may be provided in the form of a condensed liquid,but in a preferred embodiment, ethylene is provided in the form of agas. Typically, the pressure of a gaseous cross-metathesis partner overthe reaction solution is maintained in a range that has a minimum ofabout 10 psi, 50 psi, or 80 psi, and a maximum of about 100 psi, 150psi, 180 psi, 200 psi, 500 psi, 800 psi, or 1000 psi.

Procedures and Reaction Conditions

The components of the reactions of the invention may be combined in anyorder, and it will be appreciated that the order of combining thereactants may be adjusted as needed. For example, the catalyst may beadded to the olefinic substrate, followed by addition of ethylene. Asanother example, a flask containing the olefinic substrate may bepressurized with ethylene, followed by addition of the catalyst (as, forexample, a concentrated solution in a solvent as described herein). Thecatalyst may be added to the reaction either as a solid or dissolved ina solvent. The catalyst might be added in any quantities and mannereffective for the intended results of the reaction. For example inapplications where minimization of catalyst's bimolecular decompositionis desired, predetermined amounts of catalyst can be sequentially addedto the reaction mixture at predetermined time intervals.

The reactions of the invention may be carried out in a solvent, and anysolvent that is inert towards cross-metathesis may be employed.Generally, solvents that may be used in the cross-metathesis reactionsinclude organic, protic, or aqueous solvents, such as aromatichydrocarbons, chlorinated hydrocarbons, ethers, aliphatic hydrocarbons,alcohols, water, or mixtures thereof. Example solvents include benzene,toluene, p-xylene, methylene chloride, 1,2-dichloroethane,dichlorobenzene, chlorobenzene, tetrahydrofuran, diethylether, pentane,methanol, ethanol, water, or mixtures thereof. In a preferredembodiment, the reactions of the invention are carried out neat, i.e.,without the use of a solvent.

It will be appreciated that the temperature at which a cross-metathesisreaction according to the invention is conducted can be adjusted asneeded, and may be at least about −78° C., −40° C., −10° C., 0° C., 10°C., 20° C., 25° C., 40° C., 60° C., 100° C., or 150° C. In a preferredembodiment, the reactions are carried out at a temperature of at leastabout 40° C., and in another preferred embodiment, the reactions arecarried out at a temperature of at least about 60° C.

The reactions of the invention are catalyzed by any of the metathesiscatalysts that are described supra. The catalyst is typically added tothe reaction medium as a solid, but may also be added as a solutionwherein the catalyst is dissolved in an appropriate solvent. It will beappreciated that the amount of catalyst that is used (i.e., the“catalyst loading”) in the reaction is dependent upon a variety offactors such as the identity of the reactants (including the identity ofthe catalyst), and the reaction conditions that are employed. It istherefore understood that catalyst loading may be optimally andindependently chosen for each reaction. In general, however, thecatalyst will be present in an amount that ranges from a low of about0.1 ppm, 1 ppm, or 5 ppm, to a high of about 10 ppm, 15 ppm, 25 ppm, 50ppm, 100 ppm, 200 ppm, 500 ppm, 1000 ppm, or 10,000 ppm relative to theamount of the olefinic substrate. Catalyst loading, when measured in ppmrelative to the amount of the olefinic substrate, is calculated usingthe equation${{ppm}\quad{catalyst}} = {\frac{{moles}\quad{catalyst}}{{moles}\quad{olefinic}\quad{substrate}}*1\text{,}000\text{,}000}$Alternatively, the amount of catalyst can be measured in terms of mol %relative to the amount of olefinic substrate, using the equation${{mol}\%\quad{catalyst}} = {\frac{{moles}\quad{catalyst}}{{moles}\quad{olefinic}\quad{substrate}}*100}$Thus, the catalyst will generally be present in an amount that rangesfrom a low of about 0.00001 mol %, 0.0001 mol %, or 0.0005 mol %, to ahigh of about 0.001 mol %, 0.0015 mol %, 0.0025 mol %, 0.005 mol %, 0.01mol %, 0.02 mol %, 0.05 mol %, 0.1 mol %, or 1 mol % relative to theolefinic substrate.In a second embodiment of the invention, the olefin metathesis reactionis carried out by contacting, in the presence of a ruthenium alkylidenemetathesis catalyst, an olefinic substrate comprised of a mixture ofmonoglycerides, diglycerides, and triglycerides, with ethylene, underreaction conditions effective to allow cross-metathesis to occur. Theolefinic substrate comprises at least one internal olefin, and themetathesis catalyst has the structure of formula (II)

wherein:

m is zero, 1, or 2;

M is Ru or Os;

n1 and n2 are independently selected from zero and 1;

X¹ and X² are anionic ligands;

R¹ and R² are independently selected from H, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl;

L² and L³ are neutral electron donating ligands; and

L¹ is a carbene ligand with the structure of formula (IIIa)

wherein:

Z¹ is —N(Ar¹)(R⁹) and Z² is —N(Ar²)(R^(9A)) or —C(R¹⁰)(R¹¹)(R¹²);

Ar¹ and Ar² are independently aryl substituted with at least one groupselected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂ aryl,C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl; and

R⁹, R^(9A), R¹⁰, R¹¹, and R¹² are independently selected from hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl,

wherein any two of X¹, X², L¹, L², L³, R¹, R², R⁹, R^(9A), R¹⁰, R¹¹ andR¹² may be taken together to form a cycle.

The disclosure for the first embodiment of the invention (e.g.,reactants and reaction conditions described supra) also applies for thisembodiment.

In a third embodiment of the invention, the olefin metathesis reactioncomprises contacting, under reaction conditions effective to prepare aterminal olefin, an olefinic substrate comprising a seed oil or acomposition derived from a seed oil and further comprising at least oneinternal olefin with ethylene in the presence of a ruthenium alkylidenemetathesis catalyst comprising an N-heterocyclic carbene ligand, whereinat least about 50% of the metathesis reaction products comprise aterminal olefin and further wherein at least about 50% of the internalolefins initially present in the reaction mixture are converted intoterminal olefins. The disclosure for the first embodiment of theinvention (e.g., reactants and reaction conditions described supra) alsoapplies for this embodiment.

In a fourth embodiment of the invention, the olefin metathesis reactionscomprise contacting, in the presence of a metathesis catalyst, anolefinic substrate comprising at least one internal olefin withethylene, wherein the metathesis catalyst has the structure of formula(IIA)

wherein:

m is 0, 1, or 2;

n1 and n2 are independently selected from zero and 1;

X^(1A) and X^(2A) are CF₃CO₂;

R¹ and R² are independently selected from H, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl;

L² and L³ are neutral electron donating ligands; and

L^(1A) is an N-heterocyclic carbene ligand.

The disclosure for the first embodiment of the invention (e.g.,reactants and reaction conditions described supra) also applies for thisembodiment.

In a fifth embodiment of the invention, the olefin metathesis reactionscomprise contacting, under reaction conditions effective to prepare aterminal olefin, an olefinic substrate comprising a seed oil or acomposition derived from a seed oil and further comprising at least oneinternal olefin with ethylene, in the presence of a metathesis catalyst,wherein the metathesis catalyst comprises an N-heterocyclic carbeneligand and is present in an amount that is less than about 50 ppm. Thedisclosure for the first embodiment of the invention (e.g., reactantsand reaction conditions described supra) also applies for thisembodiment.

It is to be understood that while the invention has been described inconjunction with the preferred specific embodiments thereof, that thedescription above as well as the examples that follow are intended toillustrate and not limit the scope of the invention. Other aspects,advantages, and modifications within the scope of the invention will beapparent to those skilled in the art to which the invention pertains.

EXAMPLES General Procedures

Low Pressure (<200 psi) ethenolyses: Ethenolyses of research grademethyl oleate were set up under an inert atmosphere in a glove box. Asan example reaction procedure, a Fisher-Porter bottle equipped with astir bar was charged with methyl oleate (>99%) from Nu-Check-Prep(Elysian, Minn.) (15.0 g; 50.6 mmol). A solution of olefin metathesiscatalyst of an appropriate concentration was prepared in anhydrousdichloromethane (from Aldrich) and the desired volume of this solutionadded to the methyl oleate. The head of the Fisher-Porter bottle wasequipped with a pressure gauge and a dip-tube was adapted on the bottle.The system was sealed and taken out of the glove box to an ethyleneline. The vessel was then purged 3 times with ethylene (Polymer purity99.9% from Matheson Tri Gas), pressurized to the indicated pressure andplaced in an oil bath at the indicated temperature. The reaction wasmonitored by collecting samples into vials at different reaction timesvia the dip-tube. Immediately after collecting a sample, the reactionwas stopped by adding 1 mL of a 1.0 M isopropanol solution oftris-hydroxymethylphopshine (THMP) to the vial. The samples were thenheated for at least 1 hour at 60° C., diluted with 1 mL of distilledwater, extracted with 1 mL of hexanes and analyzed by gas chromatography(GC).

High pressure (>200 psi) ethenolyses: High pressure ethenolyses ofresearch grade methyl were run according to a procedure analogous tothat for low pressure ethenolyses, except that a high-pressure stainlesssteel reactor (Parr) was used in place of the Fisher-Porter bottles.

GC analytical method: The GC analyses were run using a flame ionizationdetector (FID). The following conditions and equipment were used:Column: Rtx-5, 30 m × 0.25 mm (ID) × 0.25 μm film thickness.Manufacturer: Restek GC and column conditions: Injector temperature:250° C. Detector temperature: 280° C. Oven temperature: Startingtemperature: 100° C., hold time: 1 minute. Ramp rate 10° C./min to 250°C., hold time: 12 minutes. Carrier gas: Helium Mean gas velocity: 31.3 ±3.5% cm/sec (calculated) Split ratio: ˜50:1

Example 1 Ethenolysis of MO

Ethenolysis reactions using various first and second generation Grubbscatalysts were run according to the general procedure. Data are providedin Table 1. TABLE 1 Comparison of first and second generation catalystsin ethenolysis of MO.^(a) Temp Time Conversion Selectivity Yield TOFEntry Catalyst (° C.) (min) (%)^(b) (%)^(c) (%)^(d) TON^(e) (min⁻¹)^(f)1 C823 40 120 58 93 54 5,400 45 2 C823 60 30 54 89 48 4,800 160 3 C60140 30 51 94 48 4,800 160 4 C848 40 120 64 44 28 2,800 23 5 C848 60 <1564 44 28 2,800 >190 6 C627 40 30 60 33 20 2,000 67 7 C627 60 <15 68 4732 3,200 >210^(a)General conditions: neat MO, 150 psi ethylene, catalyst loading =100 ppm^(b)Conversion = 100 − [(final moles of MO) * 100/(initial moles of MO)]^(c)Selectivity = (moles of ethenolysis products) * 100/(moles of totalproducts)^(d)Yield = (moles of ethenolysis products) * 100/(initial moles of MO)= Conversion * Selectivity/100^(e)TON = Yield * [(moles of MO)/(moles of Cat.)]^(f)TOF = TON/Time

Example 2 Ethenolysis of MO

Ethenolysis reactions using various catalysts were run according to thegeneral procedure. Data are provided in Table 2. TABLE 2 Comparison ofvarious catalysts in the ethenolysis of MO Loading Time ConversionSelectivity Yield TOF Entry Cat. (ppm) (min) (%) (%) (%) TON (min⁻¹) 1^(a) C848 100 120 64 44 28 2,800 23  2^(b) C848 100 <15 64 44 282,800 >190  3^(a) C627 100 30 60 33 20 2,000 67  4^(b) C627 100 <15 6847 32 3,200 >210  5^(a) C782 100 <15 38 71 27 2,700 >180  6^(b) C782 100<15 53 60 32 3,200 >210  7^(a) C712 100 30 70 56 39 3,900 130  8^(b)C712 100 <15 79 71 56 5,600 >373  9^(a) C712 35 <15 69 57 39 11,000 >73310^(c) C712 100 360 87 80 70 7,000 19 11^(c) C712 25 360 51 63 32 12,80036 12^(a) C933 100 60 69 55 38 3,800 63 13^(a) C933 10 60 61 36 2222,000 367 14^(a) C866 100 30 49 94 46 4,600 150 15^(b) C866 100 <15 4388 38 3,800 >250 16^(c) C866 100 <30 39 92 36 3,600 >120 17^(c) C866 500<15 86 94 81 1,620 >110 18^(d) C697 100 1260 66 53 35 3,560 <3 19^(e)C697 100 390 79 72 57 5,710 15 20^(f) C697 100 120 81 67 54 5,410 4521^(a) C785 100 1380 58 55 32 3,200 <3 22^(b) C785 100 180 78 73 575,640 31 23^(b) C859 100 240 77 66 51 5,200 22 24^(g) C859 100 30 76 6146 4,680 156 25^(a) C859 100 1200 71 59 42 4,200 <4 26^(a) C879 100 39051 69 35 3,570 9 27^(b) C879 100 240 59 90 53 5,370 22 28^(b) C965-p 10030 58 45 26 2,500 84 29^(b) C824 100 30 35 86 30 2,990 100 30^(a) C606100 1,320 61 92 56 5,600 4 31^(a) C606 50 1,200 61 93 57 11,400 1032^(a) C578 100 <30 73 73 53 5,300 >177 33^(a) C578 35 60 75 75 5616,000 267 34^(a) C578 10 <30 42 83 35 35,000 >1,167 35^(a) C646 100 36046 94 43 4,200 12 36^(a) C838 100 1320 60 90 54 5,440 4 37^(g) C577 100300 74 84 62 6,330 21 38^(b) C577 100 1380 67 90 60 6,150 <5 39^(a)C767-m 100 30 37 32 12 1,150 38 40^(a) C811 100 15 62 34 21 2,100 14041^(a) C916 100 15 65 45 29 2,900 194 42^(b) C827 100 120 75 64 48 4,79040^(a)neat MO; 40° C.; 150 psi ethylene.^(b)neat MO; 60° C.; 150 psi ethylene.^(c)neat MO; 25° C.; 800 psi ethylene.^(d)neat MO; 40° C.; 180 psi ethylene.^(e)neat MO; 60° C.; 180 psi ethylene.^(f)neat MO; 80° C.; 180 psi ethylene.^(g)neat MO; 80° C.; 150 psi ethylene

Example 3 Ethenolysis OF MO

Ethenolysis reactions using various catalysts were run according to thegeneral procedure. Data are provided in Table 3. TABLE 3 Comparison ofC606 and C578 to C848 and C627 in ethenolysis of MO^(a) Loading TimeConversion Selectivity Yield TOF Entry Cat. (ppm) (min) (%) (%) (%) TON(min⁻¹) 1 C848 100 120 64 44 28 2,800 23 2 C627 100 30 60 33 20 2,000 673 C606 100 1,320 61 92 56 5,600 4 4 C606 50 1,200 61 93 57 11,400 10 5C578 100 <30 73 73 53 5,300 >177 6 C578 35 60 75 75 56 16,000 267 7 C57810 <30 42 83 35 35,000 >1,167^(a)Conditions: neat MO; 40° C.; 150 psi ethylene.

Example 4 Ethenolysis of Pure Methyl Oleate With 2^(nd) GenerationCatalysts

As in the reaction shown below, methyl oleate was reacted with ethyleneand 100 ppm of catalyst C627 according to the general procedure givenabove. The results are illustrated in the graph shown in FIG. 1.

1. A method for synthesizing a terminal olefin, the method comprisingcontacting, in the presence of a metathesis catalyst, an olefinicsubstrate comprised of at least one internal olefin with ethylene,wherein the catalyst is present in an amount that is less than about1000 ppm relative to the amount of the olefinic substrate, and whereinthe metathesis catalyst has the structure of formula (II)

wherein: m is zero, 1, or 2; M is Ru or Os; n1 and n2 are independentlyselected from zero and 1; X¹ and X² are anionic ligands; R¹ and R² areindependently selected from H, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl; L² and L³ are neutral electron donating ligands; and L¹ isa carbene ligand with the structure of formula (IIIa)

Wherein: Z¹ is —N(Ar¹)(R⁹) and Z² is —N(Ar²)(R^(9A)) or—C(R¹⁰)(R¹¹)(R¹²); Ar¹ and Ar² are independently aryl substituted withat least one group selected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl; and R⁹,R^(9A), R¹⁰, R¹¹, and R¹² are independently selected from hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, wherein any two ofX¹, X², L¹, L², L³, R¹, R², R⁹, R^(9A), R¹⁰, R¹¹, and R¹² may be takentogether to form a cycle.
 2. The method of claim 1, wherein m is 0 andL² and R² are taken together to form a linkage Q, such that the catalysthas the structure of formula (IIa)

wherein Q is selected from hydrocarbylene, substituted hydrocarbylene,heteroatom-containing hydrocarbylene, and substitutedheteroatom-containing hydrocarbylene, wherein two or more substituentson adjacent atoms within Q may be taken together to form an additional,optionally substituted cyclic structure.
 3. The method of claim 1 or 2,wherein Z² is —C(R¹⁰)(R¹¹)(R¹²), and R⁹ and R¹² are taken together toform an optionally substituted hydrocarbylene linkage.
 4. The method ofclaim 3, wherein the linkage has the structure

such that L¹ has the structure of formula (IIIb)

wherein α is an optional double bond, and R¹⁰, R¹¹, R¹³, R¹⁴, R¹⁵, andR¹⁶ are independently selected from hydrogen, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl, wherein any two or more of Ar¹, R¹⁰,R¹¹, R¹³, R¹⁴, R¹⁵, and R¹⁶ may be taken together to form a cyclicgroup, and provided that R¹⁴ and R¹⁶ are not present if α is present. 5.The method of claim 4, wherein Ar¹ has the structure of formula (VIIa)

wherein

represents the attachment point to N in formula (IIIb), R¹⁷ and R¹⁸ areindependently selected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂alkynyl, C₂-C₁₂ aryl, C₅-C₁₂ aralkyl, and C₅-C₁₂ alkaryl, and R¹⁹, R²⁰,and R²¹ are independently selected from H, C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl,C₂-C₁₂ alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl.
 6. Themethod of claim 5, wherein R¹⁹, R²⁰, and R²¹ are H such that Ar¹ has thestructure of formula (VIIb)


7. The method of claim 6, wherein R¹⁷ and R¹⁸ are C₂-C₁₂ alkyl.
 8. Themethod of claim 7, wherein R¹⁷ and R¹⁸ are primary alkyl.
 9. The methodof claim 8, wherein R¹⁷ and R¹⁸ are ethyl.
 10. The method of claim 3,wherein R¹⁰ and R¹¹ are taken together to form a cyclic group.
 11. Themethod of claim 3, wherein α is not present.
 12. The method of claim 1or 2, wherein Z² is —N(Ar²)(R^(9A)) and R⁹ and R^(9A) are taken togetherto form an optionally substituted hydrocarbylene linkage.
 13. The methodof claim 12, wherein the linkage has the structure

such that L¹ has the structure of formula (IIIc)

wherein: α is an optional double bond; and R¹³, R¹⁴, R¹⁵, and R¹⁶ areindependently selected from hydrogen, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl, wherein any two of R¹³, R¹⁴, R¹⁵, andR¹⁶ may be taken together to form a cyclic group, and provided that R¹⁴and R¹⁶ are not present if α is present.
 14. The method of claim 13,wherein L¹ has the structure of formula (IIId)

wherein R²², R²³, R²⁷, and R²⁸ are independently selected from C₂-C₁₂alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂ aryl, C₅-C₁₂ aralkyl, andC₅-C₁₂ alkaryl, and R²⁴, R²⁵, R²⁶, R²⁹, R³⁰, and R³¹ are independentlyselected from H, C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₅-C₁₂aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl.
 15. The method of claim 14,wherein α is not present, such that L¹ has the structure of formula(IIId-1)


16. The method of claim 15, wherein R²⁴, R²⁵, R²⁶, R²⁹, R³⁰, and R³¹ areH, such that L¹ has the structure of formula (IIIe)


17. The method of claim 16, wherein R²², R¹¹, R²⁷, and R²⁸ are eachindependently C₃-C₁₂ secondary or C₄-C₁₂ tertiary alkyl.
 18. The methodof claim 17, wherein R²², R²³, R²⁷, and R²⁸ are each independentlyC₃-C₁₂ secondary alkyl.
 19. The method of claim 18, wherein R²², R²³,R²⁷, and R²⁸ are each isopropyl.
 20. The method of claim 2, wherein thecatalyst has the structure of formula (IIb)


21. The method of claim 1, wherein the catalyst is


22. The method of claim 1, wherein the olefinic substrate is selectedfrom seed oils, alkyl esters of unsaturated fatty acids, and aryl estersof unsaturated fatty acids.
 23. The method of claim 1, wherein theolefinic substrate comprises a mixture of internal olefins.
 24. Themethod of claim 23, wherein the olefinic substrate is selected frommonoacylglycerols, diacylglycerols, triacylglycerols, and combinationsthereof.
 25. The method of claim 24, wherein the monoacylglycerols,diacylglycerols, and triacylglycerols each contain at least one C₈-C₂₄unsaturated side chain.
 26. The method of claim 22, wherein the olefinicsubstrate comprises a seed oil.
 27. The method of claim 26, wherein theseed oil is soybean oil.
 28. The method of claim 26, wherein the seedoil is canola oil.
 29. The method of claim 1, wherein the contactingoccurs under an ethylene pressure in the range of about 80 psi to about1000 psi.
 30. The method of claim 29, wherein the contacting occursunder an ethylene pressure in the range of about 100 psi to about 200psi.
 31. The method of claim 1, wherein the olefinic substrate isdissolved in a solvent.
 32. The method of claim 1, wherein the catalystis present in an amount that is less than about 500 ppm relative to theolefinic substrate.
 33. The method of claim 32, wherein the catalyst ispresent in an amount that is less than about 200 ppm relative to theolefinic substrate.
 34. An olefin metathesis process comprisingcontacting, under reaction conditions effective to prepare a terminalolefin, an olefinic substrate comprising at least one internal olefinand further comprising a mixture of mono-, di-, and tri-glycerides withethylene in the presence of a ruthenium alkylidene metathesis catalystthat has the structure of formula (II)

wherein: m is zero, 1, or 2; M is Ru or Os; n1 and n2 are independentlyselected from zero and 1; X¹ and X² are anionic ligands; R¹ and R² areindependently selected from H, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl; L² and L³ are neutral electron donating ligands; and L¹ isa carbene ligand with the structure of formula (IIIa)

wherein: Z¹ is —N(Ar¹)(R⁹) and Z² is —N(Ar²)(R^(9A)) or—C(R¹⁰)(R¹¹)(R¹²); Ar¹ and Ar² are independently aryl substituted withat least one group selected from C₂-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₂-C₁₂alkynyl, C₅-C₁₂ aryl, C₆-C₁₂ aralkyl, and C₆-C₁₂ alkaryl; and R⁹,R^(9A), R¹⁰, R¹¹, and R¹² are independently selected from hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, wherein any two ofX¹, X², L¹, L², L³, R¹, R², R⁹, R^(9A), R¹⁰, R¹¹, and R¹² may be takentogether to form a cycle.
 35. An olefin metathesis process comprisingcontacting, under reaction conditions effective to prepare a terminalolefin, an olefinic substrate comprising a seed oil or a compositionderived from a seed oil and further comprising at least one internalolefin, with ethylene in the presence of a ruthenium alkylidenemetathesis catalyst comprising an N-heterocyclic carbene ligand, whereinat least about 50% of the metathesis reaction products comprise aterminal olefin and further wherein at least about 50% of the internalolefins initially present in the reaction mixture are converted toterminal olefins.
 36. A method for synthesizing a terminal olefin, themethod comprising contacting, in the presence of a metathesis catalyst,an olefinic substrate comprising at least one internal olefin withethylene, wherein the metathesis catalyst has the structure of formula(IIA)

wherein: m is 0, 1, or 2; n1 and n2 are independently selected from zeroand 1; X^(1A) and X^(2A) are CF₃CO₂; R¹ and R² are independentlyselected from H, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl; L² and L³ are neutral electron donating ligands; and L^(1A)is an N-heterocyclic carbene ligand.
 37. A method for synthesizing aterminal olefin, the method comprising contacting, under reactionconditions effective to prepare a terminal olefin, an olefinic substratecomprising a seed oil or a composition derived from a seed oil, andfurther comprising at least one internal olefin, with ethylene in thepresence of a metathesis catalyst, wherein the metathesis catalystcomprises an N-heterocyclic carbene ligand and is present in an amountthat is less than about 50 ppm relative to the olefinic substrate.